CabinBoy,
The QF Thai based Cabin crew are on approx A$700 per month with no benefits such as staff travel, unpaid stand-bys (and even if the cost of living IS lower, they are all still being underpaid compared to many of their old jobs...'some-one' told them the wrong salary.)
BA are recruiting in Thailand at the moment, with proper wages and benefits on offer...I can't wait to see what happens in the next 6 months
Quite possibly, non-membership of a union may be written into a contract. I'm not sure of the legalities of such a thing, but rest assured if it can be done - it will.
Slavery comes in many forms.